Interest in solar thermal power has risen in recent years. Concentrating solar power (CSP) is the lowest cost solar power technology at utility scale. However, the costs are still too high to be competitive without government support. Reducing the capital costs by about 50% will make CSP competitive with conventional resources without government incentives.
Some of the reductions in cost will come from economy of scale and minor design innovations. However, additional cost reductions will have to come from improvements in the power conversion efficiencies. In a 100 megawatt (MW) CSP plant, each 1% improvement in the overall plant efficiency can result in a reduction of approximately $20 million in capital costs at current prices. The overall efficiency of a CSP plant is the product of the efficiencies of the solar field and the power block. Therefore, it is important to look at the potential improvements in the efficiencies of both the solar field and the power block. The solar field efficiency depends on the efficiency of the solar collectors being used in the field, while the efficiency of the power block depends on the efficiencies of the thermodynamic cycles used in the power block in addition to the efficiencies of the equipment such as the turbine and the heat exchangers.